The present invention relates to a high-frequency treatment apparatus which can be inserted into a vital body cavity to coagulate/incise tissue.
Generally, bipolar forceps having jaws as a pair of grasping members for grasping vital tissue and high-frequency current supply electrodes formed on the jaws are known. In use of this bipolar forceps, vital tissue to be treated is grasped between the pair of jaws, and a high-frequency current is flowed across the electrodes of the jaws, thereby coagulating the vital tissue between the jaws.
Bipolar forceps of this type are normally used for various purposes, e.g., to stop bleeding from blood vessels in vital tissue, cauterize a morbid portion or bleeding point on the surface of vital tissue, or close a uterine tube for contraception. The bipolar forceps are used for vascular hemostasis or tubal ligation; they coagulate vital tissue of a patient to be treated and also incise the coagulated vital tissue.
Conventionally, as high-frequency treatment tools of this type, a tool having projections formed on jaws so as to coagulate/incise tissue upon manipulating a manipulation portion, as disclosed in, e.g., Japanese Patent Application No. 10-11199, a tool having two insulated electrodes on the outer surfaces of a surgical scissors comprising a pair of shearing members so as to coagulate/incise tissue, as disclosed in Jpn. Pat. Appln. KOKAI Publication No. 9-173347, and a tool having two opposing coagulation electrodes and a slidable incision electrode at the center so as to incise tissue using one of the coagulation electrodes and the incision electrode, as disclosed in DE 4138116 A1 are known.
DE 4032471 C2 (corresponding to U.S. Pat. No. 5,269,780) discloses a tool which has coagulation electrodes and incision electrode at the distal end of the insertion portion and a change-over switch provided on the manipulation portion to switch the energization state between the coagulation electrodes and between the incision electrode and coagulation electrodes, thereby coagulating/incising tissue. Arrangements in DE 4138116 A1 and U.S. Pat. No. 5,267,998 also have similar switches.
In addition, as disclosed in Jpn. Pat. Appln. KOKAI Publication No. 9-108234, a tool which coats the energization portions of jaws with an insulating material to increase the current density and increase the coagulation speed is also known.
Furthermore, a bipolar coagulation/incision treatment tool disclosed in U.S. Pat. No. 2,031,682 which coagulates tissue using a coagulation electrode and then incises the tissue using an incision electrode, or a tool disclosed in U.S. Pat. No. 4,655,216 which coagulates tissue using a coagulation electrode and then cuts the tissue with scissors-shaped blades is also known.
However, the tool disclosed in Japanese Patent Application No. 10-11199 cannot sufficiently coagulate tissue in some cases because the tissue is coagulated/incised using only an incision output. Additionally, the tool disclosed in Jpn. Pat. Appln. KOKAI Publication No. 9-173347 is a surgical scissors that can incise tissue in accordance with manipulation of the physician even without coagulation, and therefore, bleeding may occur.
As the tool disclosed in DE 4138116 A1 has no jaws for grasping tissue, it cannot sufficiently close and coagulate a blood vessel. In the tool disclosed in DE 4032471 C2, if the physician incises tissue by switching the change-over switch of the manipulation portion between coagulation and incision before the tissue completely coagulates, bleeding may occur. The change-over switch merely switches the energization state. To switch between the coagulation output and the incision output, for example, a foot switch must be operated with a foot simultaneously with the operation of the change-over switch. For this reason, the operation not only is cumbersome but also cannot continuously and smoothly switch from coagulation to incision.
For the tool disclosed in Jpn. Pat. Appln. KOKAI Publication No. 9-108234, the jaws must be coated with an electrical insulating material.
For the tool disclosed in U.S. Pat. No. 2,031,682, after coagulation, the user must operate an incision means different from the coagulation means. This makes the operability poor and also poses a problem of interruption of operation. In addition, the scissors-like blades of the tool disclosed in U.S. Pat. No. 4,655,216 are poor in durability and become blunt after repeated use.